There are validation issues in your addon.
You have:
<div id="$id" class="tborder content_block">
<h4 class="thead block_title">
<a href="#top" class="collapse_gadget" onclick="return toggle_collapse('ads')"><img id="collapseimg_ads" src="$stylevar[imgdir_button]/collapse_generic{$vbcollapse['collapseimg_ads']}.gif" alt="" border="0" /></a>
<a name="ads"></a>
<span class="block_name">ADS</span>
</h4>
<div class="block_content" id="collapseobj_ads" style="{$vbcollapse['collapseobj_ads']}">
<div class="alt1 smallfont block_row">
$adscode
</div>
</div>
</div>
But better would be:
<div id="ads" class="tborder content_block">
<h4 class="thead block_title">
<a href="#top" class="collapse_gadget" onclick="return toggle_collapse('ads')"><img id="collapseimg_ads" src="$stylevar[imgdir_button]/collapse_generic{$vbcollapse['collapseimg_ads']}.gif" alt="" border="0" /></a>
<a name="ads"></a>
<span class="block_name">ADS</span>
</h4>
<div class="block_content" id="collapseobj_ads" align="center">
<table cellpadding="0" cellspacing="0" border="0" class="tborder" width="$stylevar[tablewidth]" align="center">
<tr>
<td>
<table cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%">
<tr align="center">
<td class="alt1">$adscode</td>
</tr>
</table>
</td>
</tr>
</table>
</div>
</div>
Demo: http://www.2-wheel-planet.de/members/kolbi.html
(the placement is changed by myselfes)